HTML5 canvas像素化效果

HTML5 canvas pixelate effect. New great HTML5 tutorial – I going to tell you about creating pixelate photo effect with html5 (at canvas). More, this is not static effect, but it will be pixelating all time.

HTML5 canvas像素化效果。新的很棒HTML5教程–我将告诉您有关使用html5(在画布上)创建像素化照片效果的信息。而且，这不是静态效果，但是会一直像素化。

Here are our demo and downloadable package:

这是我们的演示和可下载的软件包：

现场演示

[sociallocker]

[社交储物柜]

打包下载

[/sociallocker]

[/ sociallocker]

Ok, download the source files and lets start coding !

好的，下载源文件并开始编码！

步骤1. HTML (Step 1. HTML)

As usual – very small HTML code

和往常一样–非常小HTML代码

index.html (index.html)

<!DOCTYPE html>
<html  >
    <head>
        <meta charset="utf-8" />
        <title>HTML5 pixelate effect | Script Tutorials</title>
        <link href="css/main.css" target="_blank" rel="external nofollow"  target="_blank" rel="external nofollow"  rel="stylesheet" type="text/css" />
        <script type="text/javascript" src="js/script.js"></script>
    </head>
    <body>
        <header>
            <h2>HTML5 pixelate effect</h2>
            <a href="https://www.script-tutorials.com/html5-canvas-pixelate-effect/" target="_blank" rel="external nofollow"  target="_blank" rel="external nofollow"  target="_blank" rel="external nofollow"  class="stuts">Back to original tutorial on <span>Script Tutorials</span></a>
        </header>
        <div class="container">
            <div class="contr">
                <input type="radio" name="mode" onchange="changeMode(0)" checked /><label>Original image</label>
                <input type="radio" name="mode" onchange="changeMode(1)" /><label>Opacity channel</label>
                <input type="radio" name="mode" onchange="changeMode(2)" /><label>White channel</label>
                <input type="radio" name="mode" onchange="changeMode(3)" /><label>Color channel</label>
            </div>
            <canvas id="panel" width="800" height="600"></canvas>
        </div>
    </body>
</html>

<!DOCTYPE html>
<html  >
    <head>
        <meta charset="utf-8" />
        <title>HTML5 pixelate effect | Script Tutorials</title>
        <link href="css/main.css" target="_blank" rel="external nofollow"  target="_blank" rel="external nofollow"  rel="stylesheet" type="text/css" />
        <script type="text/javascript" src="js/script.js"></script>
    </head>
    <body>
        <header>
            <h2>HTML5 pixelate effect</h2>
            <a href="https://www.script-tutorials.com/html5-canvas-pixelate-effect/" target="_blank" rel="external nofollow"  target="_blank" rel="external nofollow"  target="_blank" rel="external nofollow"  class="stuts">Back to original tutorial on <span>Script Tutorials</span></a>
        </header>
        <div class="container">
            <div class="contr">
                <input type="radio" name="mode" onchange="changeMode(0)" checked /><label>Original image</label>
                <input type="radio" name="mode" onchange="changeMode(1)" /><label>Opacity channel</label>
                <input type="radio" name="mode" onchange="changeMode(2)" /><label>White channel</label>
                <input type="radio" name="mode" onchange="changeMode(3)" /><label>Color channel</label>
            </div>
            <canvas id="panel" width="800" height="600"></canvas>
        </div>
    </body>
</html>

步骤2. CSS (Step 2. CSS)

css / main.css (css/main.css)

I am not sure if this is necessary to publish layout page styles today, lets keep it in package today, ok?

我不确定今天是否需要发布布局页面样式，今天就将其保存在包装中，好吗？

步骤3. JS (Step 3. JS)

js / script.js (js/script.js)

// variables
var canvas, ctx;
var imgObj;
var imgd;
var iOpSize = 40;
var iMode = 0;
var iCDif = 80;
var r0, r1, r2, r3, r4, r5, r6 = 0;
// util functions
function changeMode(i) {
    iMode = i;
}
function getRand(x, y) {
    return Math.floor(Math.random()*y)+x;
}
// drawing functions
function clear() { // clear canvas function
    ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
}
function drawScene() { // main drawScene function
    clear(); // clear canvas
    // draw original image
    ctx.drawImage(imgObj, 0, 0, canvas.width, canvas.height);
    if (iMode) {
        // .. and get its data
        imgd = ctx.getImageData(0, 0, canvas.width, canvas.height);
        var data = imgd.data;
        for (var y = 0; y < canvas.height; y+=iOpSize){
            for (var x = 0; x < canvas.width; x+=iOpSize){
                // different modes
                if (iMode == 1) {
                    r0 = 55 + Math.random() * 200;
                    r1 = r2 = r3 = r4 = r5 = r6 = 0;
                } else if (iMode == 2) {
                    r0 = 255;
                    r1 = r3 = r5 = getRand(-iCDif, iCDif * 2);
                    r2 = r4 = r6 = getRand(0, iCDif);
                } else if (iMode == 3) {
                    r0 = 255;
                    r1 = getRand(-iCDif, iCDif * 2);
                    r2 = getRand(0, iCDif);
                    r3 = getRand(-iCDif, iCDif * 2);
                    r4 = getRand(0, iCDif);
                    r5 = getRand(-iCDif, iCDif * 2);
                    r6 = getRand(0, iCDif);
                }
                for (var y2 = 0; y2 < iOpSize; y2++){
                    for (var x2 = 0; x2 < iOpSize; x2++){
                        var i = ((y + y2) * canvas.width + x + x2) * 4;
                        data[i+0] = data[i+0] - r1 + r2;
                        data[i+1] = data[i+1] - r3 + r4;
                        data[i+2] = data[i+2] - r5 + r6;
                        data[i+3] = r0;
                    }
                }
            }
        }
        ctx.putImageData(imgd, 0, 0);
    }
}
// binding onload event
if (window.attachEvent) {
    window.attachEvent('onload', main_init);
} else {
    if(window.onload) {
        var curronload = window.onload;
        var newonload = function() {
            curronload();
            main_init();
        };
        window.onload = newonload;
    } else {
        window.onload = main_init;
    }
}
function main_init() {
    // creating canvas and context objects
    canvas = document.getElementById('panel');
    ctx = canvas.getContext('2d');
    // loading source image
    imgObj = new Image();
    imgObj.onload = function () {
        ctx.drawImage(imgObj, 0, 0, canvas.width, canvas.height); // Draw the image on the canvas
        imgd = ctx.getImageData(0, 0, canvas.width, canvas.height);
    }
    imgObj.src = 'images/01.jpg';
    setInterval(drawScene, 150); // loop drawScene // 30
}

// variables
var canvas, ctx;
var imgObj;
var imgd;
var iOpSize = 40;
var iMode = 0;
var iCDif = 80;
var r0, r1, r2, r3, r4, r5, r6 = 0;
// util functions
function changeMode(i) {
    iMode = i;
}
function getRand(x, y) {
    return Math.floor(Math.random()*y)+x;
}
// drawing functions
function clear() { // clear canvas function
    ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
}
function drawScene() { // main drawScene function
    clear(); // clear canvas
    // draw original image
    ctx.drawImage(imgObj, 0, 0, canvas.width, canvas.height);
    if (iMode) {
        // .. and get its data
        imgd = ctx.getImageData(0, 0, canvas.width, canvas.height);
        var data = imgd.data;
        for (var y = 0; y < canvas.height; y+=iOpSize){
            for (var x = 0; x < canvas.width; x+=iOpSize){
                // different modes
                if (iMode == 1) {
                    r0 = 55 + Math.random() * 200;
                    r1 = r2 = r3 = r4 = r5 = r6 = 0;
                } else if (iMode == 2) {
                    r0 = 255;
                    r1 = r3 = r5 = getRand(-iCDif, iCDif * 2);
                    r2 = r4 = r6 = getRand(0, iCDif);
                } else if (iMode == 3) {
                    r0 = 255;
                    r1 = getRand(-iCDif, iCDif * 2);
                    r2 = getRand(0, iCDif);
                    r3 = getRand(-iCDif, iCDif * 2);
                    r4 = getRand(0, iCDif);
                    r5 = getRand(-iCDif, iCDif * 2);
                    r6 = getRand(0, iCDif);
                }
                for (var y2 = 0; y2 < iOpSize; y2++){
                    for (var x2 = 0; x2 < iOpSize; x2++){
                        var i = ((y + y2) * canvas.width + x + x2) * 4;
                        data[i+0] = data[i+0] - r1 + r2;
                        data[i+1] = data[i+1] - r3 + r4;
                        data[i+2] = data[i+2] - r5 + r6;
                        data[i+3] = r0;
                    }
                }
            }
        }
        ctx.putImageData(imgd, 0, 0);
    }
}
// binding onload event
if (window.attachEvent) {
    window.attachEvent('onload', main_init);
} else {
    if(window.onload) {
        var curronload = window.onload;
        var newonload = function() {
            curronload();
            main_init();
        };
        window.onload = newonload;
    } else {
        window.onload = main_init;
    }
}
function main_init() {
    // creating canvas and context objects
    canvas = document.getElementById('panel');
    ctx = canvas.getContext('2d');
    // loading source image
    imgObj = new Image();
    imgObj.onload = function () {
        ctx.drawImage(imgObj, 0, 0, canvas.width, canvas.height); // Draw the image on the canvas
        imgd = ctx.getImageData(0, 0, canvas.width, canvas.height);
    }
    imgObj.src = 'images/01.jpg';
    setInterval(drawScene, 150); // loop drawScene // 30
}

How to pixelate? I have thinking for some time, and understood that this is not so difficult. We will split our image to sub-regions, and then, we will change colors (or opacity) of each region separately.

如何像素化？我已经思考了一段时间，并且了解到这并不困难。我们将图像划分为多个子区域，然后分别更改每个区域的颜色(或不透明度)。

现场演示

结论 (Conclusion)

Today’s lesson has turned a simple and interesting, isn’t it? Welcome back to read something new and interesting. Good luck in your projects.

今天的课程变得简单而有趣，不是吗？欢迎回来阅读一些有趣的新东西。在您的项目中祝您好运。

翻译自: https://www.script-tutorials.com/html5-canvas-pixelate-effect/

HTML5 canvas像素化效果

现场演示

打包下载

步骤1. HTML (Step 1. HTML)

index.html (index.html)

步骤2. CSS (Step 2. CSS)

css / main.css (css/main.css)

步骤3. JS (Step 3. JS)

js / script.js (js/script.js)

现场演示

结论 (Conclusion)

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